已知3X²-2y=4,-X²-3y=3,问:①4X²+y=( ) ②2X²-5y

已知3X²-2y=4,-X²-3y=3,问:①4X²+y=( ) ②2X²-5y 已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y 已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y² 已知x,y满足x²+y²-4x+6y+13=0则(3x+y)²-(3x+y)(3x-y)的 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知x²+|y+x|=x-1/4,求（3x+y）²（2x-y）²-（4x²+y& 4x+5y=105,2x+3y=178,x,y等于 已知x,y的值满足方程组x+2y=3,x-y=-2,求x/(x-y)²+x²-y²/(x+ 已知x²+y²+5=2x+4y,求代数式（2x²-（x+y)(x-y))x((x+y-1) 已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-( 已知4x²y-3y²=7,3x²y+4y²=19,求11x²y-2y& 已知x²+4x+y²-2y+5=0,则x+y=